The current proposal is for follow-up and continuing studies of subjects originally enrolled in a cohort-sequential investigation of adolescent cigarette smoking. Cohorts of 6th-12th graders (total N=8,521) were originally followed between 1980-1983 with the goal of prospectively predicting adolescent smoking initiation form social psychological factors. An additional follow-up was conducted in 1987-1988 when subjects ranged in age form 15-25 (mean age=20), with 73% participation. At the proposed follow-up, subjects will range in age from 21-31. The existing data set is characterized by its large sample size, depth and breadth of measures, large age span of assessment, and substantial sample retention, all of which make it a unique resource for the proposed studies. The proposed research has two major goals. First we will place cigarette smoking in the context of normal adult development. We will describe the natural history of smoking behavior from adolescence to young adulthood, and well relate cigarette smoking to the normal developmental tasks of this age period. We will assess the mutual influence between cigarette smoking and the tasks of work, marriage, and parenthood both in terms of occupancy of these social roles and in terms of the qualities of the roles (i.e., stressors, conflicts, and satisfactions). A unique feature of this project will be a study of the inter-generational transmission of cigarette smoking. We will examine our subjects socialization practices for socializing smoking behavior (or nonsmoking behavior) in their own children. By using our existing longitudinal data base, we will identify the adolescent antecedents of these strategies as well as their relations to emerging smoking behavior and smoking-related attitudes and beliefs in the next generation. The second goal of the research is to focus in more detail on subgroups within our data set that are of theoretical importance for understanding smoking behavior or of practical public health significance because of their smoking rates. These subgroups include the with a family history of smoking, those with low levels of educational attainment, and those who maintain a regular but low "nonaddictive" level of smoking behavior ("chippers"). The proposed studies will identify the adolescent antecedents, adult outcomes, and mediating mechanisms underlying smoking behavior in these important subgroups. The results of the studies will have important implications both for building theories of smoking behavior and for designing public health interventions to deter smoking among high risk groups. GRANTS=R44MH46152 Dysfunction of serotonergic (5-HT) systems in the brain have been implicated in neurological and psychiatric conditions. The progress in the study of the role of 5-HT receptor systems in the brain has relied considerable on techniques of radiolabeling using ligands of high specific activity. However, this technique for visualizing and/or monitoring brain 5-HT receptors has limitations of resolution and detection capability. Development of molecular probes for 5-HT receptors will be continued during the Phase II of this project. Fluorescent and biotin probes will be prepared for 5-HT1A, 5-HT2 and 5-HT receptor subtypes. First, the affinity and selectivity of these compounds for multiple 5-HT3 receptors will be evaluated. Selected probes will be used in the fluorescent microscopic study of 5-HT receptors on slide-mounted tissue sections. Receptor-selective molecular probes will permit detection of receptors by fluorescence and electron microscopy, will be useful in mapping cellular and subcellular distribution of 5-HT receptors, prior to and after drug treatment, for monitoring receptor mobility, and for sorting of cells 5_HT receptors on slide-mounted tissue sections.